Problem DALTSUM from SPOJ

mani1996 · Oct 17, 2016 · 2951b96 · 2951b96
1 parent e76a249
commit 2951b96
Showing 1 changed file with 37 additions and 0 deletions.
diff --git a/DALTSUM.cpp b/DALTSUM.cpp
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+// Problem : DALTSUM from SPOJ
+
+#include <bits/stdc++.h>
+#define ll long long
+using namespace std;
+
+#define MOD 1000000007
+
+ll power(ll n){
+	ll res = 1,temp = 2;
+	while(n){
+		if(n%2)res*=temp;
+		n/=2;
+		temp*=temp;
+		if(res>=MOD)res%=MOD;
+		if(temp>=MOD)temp%=MOD;
+	}
+	return res;
+}
+
+int main(){
+	int n,i;
+	cin>>n;
+	ll v,x;
+	for(i=0;i<n;i++){
+		cin>>x;
+		if(i==0){
+			v = x;
+		}
+		else{
+			v = max(v,x);
+		}
+	}
+	v = ((v%MOD)+MOD)%MOD;
+	cout<<(v*power(n-1))%MOD;
+	return 0;
+}